DESCRIPTION: Pain is characterized by complex physiological and perceptual responses, which appear to differ for females and males. For example, females show greater prevalence of many pain related disorders and enhanced perceptual responses to noxious stimuli compared to males, while males exhibit greater cardiovascular responses during painful tasks. However, the nature and clinical relevance of these gender differences in responses to painful stimuli remain unclear. The overall goal of these studies is to determine the nature of gender differences in physiological and perceptual responses to noxious stimuli, and to ascertain whether these responses are predictive of pain in the natural environment. In experiment 1, sensory (i.e., pain intensity) and affective (i.e., pain unpleasantness) responses to thermal, mechanical, pressure, ischemic, and cold pressor pain, as well as temporal summation of C fiber mediated pain in response to repetitive thermal stimuli will be compared in 75 females and 75 age matched males. In addition to these perceptual measures, physiological responses including salivary cortisol, cardiovascular and facial electromyographic response to thermal, ischemic, and cold pressor stimuli will be assessed. In Experiment 2, naturally occurring pain will be assessed over a 12 month period in subjects who complete Experiment 1, in order to determine whether laboratory pain responses predict the occurrence of pain in the natural environment. The results of this research will provide important information concerning the nature of gender differences in perceptual and physiological responses to painful stimuli. Additionally, the predictive validity of laboratory pain responses in females and males will be examined. The findings from these experiments in experimental and clinical pain responses, may ultimately lead to more effective diagnosis and treatment of gender related pain disorders.